The invention relates to a flame-retardant thermoplastic molding composition based on aliphatic polyamides, to processes for producing the same, and to use of the same for producing moldings, fibers, or foils, also to moldings, fibers, or foils produced therefrom.
The prior art discloses the use of cyclic phenoxyphosphazenes in flame-retardant polyamide resin compositions. EP-A-2 100 919 relates to flame-retardant polyamide resins which comprise, alongside a polyamide resin, a flame-retardant substance comprising phosphorus, and glass fibers. The phosphorus-containing substance can be one selected from reaction products of melamine with phosphoric acid, from (di)phosphinate salts, and also phosphazene compounds, in particular from cyclic phenoxyphosphazene compounds.
US-A-2010/0261818 relates to halogen-free, flame-retardant polyamide compositions which can be used in electrical applications. The polyamide resins comprise a phosphinate, a phosphazene, and optionally a flame-retardant synergistic compound selected from specific oxides. Phenoxyphosphazenes are examples of cyclic phosphazenes that can be used.
The flame-retardant effect of the previously known flame-retardant polyamide compositions is not yet adequate for all applications. In particular, some of the flame times are still too long.